Hi guys, having a surging idle problem with a freshly rebuilt KA24DE and I'm also getting a code 34 off the ECU, which I believe is knock sensor. Here are the details:

-93 KA24DE swapped into 89 chassis
-Motor was from an automatic car, I'm using the 89 tranny and 93 automatic ECU, with a tranny harness from a 91-93 manual.
-Freshly rebuilt
-On start up, engine surges between 1800-2300 RPM
-When I clamp off the hose to the IACV, the engine stops surging and holds a steady idle at 1800RPM
-I removed the IACV and cleaned it, but it hasn't changed anything
-Carbon canister and PAIR valve have both been removed as I didn't have them with the swap. The four vacuum lines for them have been capped off near the throttle body
-I have been starting the car with a booster pack and don't have a battery installed, just running right off the booster pack. Picking up a battery today.
-Ignition timing was properly set. (At TDC, slid in the CAS so that the rotor lined up with #1 and was facing towards the front of the car)
-ECU is giving me Code 34 Detonation sensor circuit
-Car has been sitting for a year at least before the engine was swapped in, so the gas is at least a year old.

Does anyone have any idea of what might be causing these issues?

Just as an update in case anybody finds this thread on a search. The problem was the throttle body and iacv. The throttle body was slightly bent (engine came from a donor car that was in a front end collision) causing the throttle plat to not quite close properly. Swapped on a new throttle body and the idle smoothed right out. However the the throttle was still sticky... when you blipped the throttle at idle, it held for quite a while then finally dropped. Although I had already cleaned the IACV I decided to replaced it with one from a different motor and it solved that issue as well!